Update README

Author: oreshinya

README.md

@@ -4,6 +4,20 @@
 
 Simple [JWT(JSON Web Token)](http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html) encoder and decoder for PureScript.
 
+## Installation
+
+### Bower
+
+```
+$ bower install purescript-simple-jwt
+```
+
+### Spago
+
+```
+$ spago install simple-jwt
+```
+
 ## Documentation
 
 Module documentation is [published on Pursuit](http://pursuit.purescript.org/packages/purescript-simple-jwt).